title: Preconditioning mesenchymal stem cells with caspase inhibition and hyperoxia prior to hypoxia exposure increases cell proliferation.
abstract: Myocardial infarction is a leading cause of mortality and morbidity worldwide. Occlusion of a coronary artery produces ischemia and myocardial necrosis that leads to left ventricular (LV) remodeling, dysfunction, and heart failure. Stem cell therapy may decrease infarct size and improve LV function; the hypoxic environment, however, following a myocardial infarction may result in apoptosis, which in turn decreases survival of transplanted stem cells. Therefore, the effects of preconditioned mesenchymal stem cells (MSC) with hyperoxia (100% oxygen), Z-VAD-FMK pan-caspase inhibitor (CI), or both in a hypoxic environment in order to mimic conditions seen in cardiac tissue post-myocardial infarction were studied in vitro. MSCs preconditioned with hyperoxia or CI significantly decreased apoptosis as suggested by TUNEL assay and Annexin V analysis using fluorescence assisted cell sorting. These effects were more profound when both, hyperoxia and CI, were used. Additionally, gene and protein expression of caspases 1, 3, 6, 7, and 9 were down-regulated significantly in MSCs preconditioned with hyperoxia, CI, or both, while the survival markers Akt1, NF-κB, and Bcl-2 were significantly increased in preconditioned MSCs. These changes ultimately resulted in a significant increase in MSC proliferation in hypoxic environment as determined by BrdU assays compared to MSCs without preconditioning. These effects may prove to be of great clinical significance when transplanting stem cells into the hypoxic myocardium of post-myocardial infarction patients in order to attenuate LV remodeling and improve LV function.
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio.
authors.forename: Uksha
authors.initials: U
authors.lastname: Saini
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gumina
authors.forename: Brian
authors.initials: B
authors.lastname: Wolfe
authors.forename: M Lakshmi
authors.initials: ML
authors.lastname: Kuppusamy
authors.forename: Periannan
authors.initials: P
authors.lastname: Kuppusamy
authors.forename: Konstantinos Dean
authors.initials: KD
authors.lastname: Boudoulas
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D020170:Caspase 1 / Q000235:genetics / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053178:Caspase 6 / Q000235:genetics / Q000378:metabolism; D053179:Caspase 7 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D015687:Cell Hypoxia / Q000502:physiology*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D051381:Rats
chemical_list: D000590:Amino Acid Chloromethyl Ketones; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C505410:Casp3 protein, rat; C505518:Casp6 protein, rat; C506435:Casp9 protein, rat; D053148:Caspase 3; D053178:Caspase 6; D053179:Caspase 7; D053453:Caspase 9; D020170:Caspase 1
keywords: APOPTOSIS; CASPASE INHIBITOR; HYPEROXIA; HYPOXIA; MESENCHYMAL STEM CELLS; PRECONDITIONING